If A is an invertible matrix of order 3, then Match List-I with List-II
Choose the correct answer from the options given below: |
(A)-(II), (B)-(IV), (C)-(I), (D)-(III) (A)-(I), (B)-(II), (C)-(III), (D)-(IV) (A)-(III), (B)-(IV), (C)-(I), (D)-(II) (A)-(IV), (B)-(III), (C)-(II), (D)-(I) |
(A)-(II), (B)-(IV), (C)-(I), (D)-(III) |
The correct answer is Option (1) → (A)-(II), (B)-(IV), (C)-(I), (D)-(III)
Given: $A$ is an invertible $3\times 3$ matrix. (A) $|\text{adj }A|$ For $n\times n$: $|\text{adj }A| = |A|^{\,n-1}$. Here $n=3$, so $|\text{adj }A| = |A|^2$. Matches (II) (B) $|A(\text{adj }A)|$ $A(\text{adj }A)=|A|I$, so determinant $=|A|^3$. Matches (IV) (C) $|2A|$ $|kA|=k^n|A|$ with $n=3$, so $|2A|=2^3|A|=8|A|$. Matches (I) (D) $|A^{-1}|$ $|A^{-1}|=\frac{1}{|A|}$. Matches (III) The correct matching is: A–II, B–IV, C–I, D–III. |